Scottish seagrass in a changing ocean; their health, role and restoration potential

Summary
This PhD will establish the current state of health of seagrass in Scotland, assess methods for successful cultivation and restoration of seagrass, and examine the most effective routes for future conservation of this habitat in Scotland.

Project background
Seagrass is one of the most valuable ecosystems on the planet, providing a range of invaluable ecosystem services (1). Seagrass is also one of the most efficient natural carbon sinks in the world, proving crucial in an age of climate change. However, this critical ecosystem has declined by 92% in the last 100 years in the UK (2), with a lack of knowledge about the ecosystem being one of the major issues facing conservation of seagrass in Scotland and the UK. Scotland has 20% of north west Europe’s seagrass coverage (3), yet the health and societal benefits of seagrass in Scotland is unknown. A recent study (4) investigating the health of Zostera marina (the most abundant seagrass species in the UK) in UK waters excluding Scotland, highlighted that seagrass was in very poor health compared with other countries. Understanding the health of seagrass in Scotland is therefore crucial for future conservation efforts and protection. Due to seagrass’s carbon storage potential, seagrass restoration could prove an important nature-based solution to climate change in Scotland. Furthermore, the high diversity associated with these habitats means that restoring them will help address the unprecedented global biodiversity loss reported by the UN (5). It is therefore crucial that we understand a suitable and efficient method of restoring seagrass in Scotland as well as defining baseline measures of seagrass health and ecosystem function (6). With our ocean conditions also changing at an unprecedented rate, we also need to consider how robust and sustainable conservation methods are in both the short and long term. Knowing the status of seagrass in Scotland in addition to societal benefits will help determine the impact of restoration trials and contribute to successful conservation efforts going forward. Scotland has a well-established coastal communities network with the goal to harness long-term solutions to ensure healthy, well managed seas. Engagement with these groups as the project develops would help assess the efficiency and long term sustainability of outcomes from this project.

Research questions
1. Where are Scottish Seagrass habitats and how healthy are they?

2. What are the most efficient methods for restoration, and how can this be scaled up for community efforts?

3. What are the prospects of efficient seagrass restoration in Scotland?

Methodology
Seagrass meadows will be surveyed using novel techniques and mapped out using GIS. The health of seagrass will be assessed by recording seagrass density, morphology and leaf biochemistry. Leaf samples will then be analysed in the lab to establish the levels of carbon, nitrogen and phosphorus, which can then be compared with data from the rest of the UK and globally to establish the current health of seagrass in Scotland. Methods of seed collection will be assessed to establish the most efficient method of collection. The seeds will then be allowed to germinate, with varying conditions used to find the optimal germination conditions.

At the restoration sites, the environmental factors and conditions will be recorded to better understand the factors controlling successful seagrass restoration. Growth rates of seagrass shoots as well as success ratio of seeds will be recorded to assess the efficiency of the restoration techniques, while measures of ecosystem function (e.g. faunal communities, water quality) will help assess the wider ecological and societal benefits. Scotland also has a well-established coastal community network, and engagement with this network would be an essential part of the analysis of how efficient and sustainable future restoration efforts would be.

Training
The School of GeoSciences at the University of Edinburgh has a large research student cohort that will provide peer-support throughout the research program. The multi-disciplinary nature of the project and of the supervisory team will ensure that the scholar experiences training in multiple fields across different campuses, including biology, ecology and biogeochemistry. A comprehensive training programme will be provided comprising both specialist scientific training and generic transferable and professional skills. The scholar will be encouraged to attend specialist courses that will directly contribute to the proposed project, such as GIS mapping. Analytical training will be provided by the supervisors or technicians for all instrumentation required.

Supervisors
Sebastian Hennige, University of Edinburgh
[Email Address Removed]
www.research.ed.ac.uk/portal/en/persons/sebastian-hennige(6177a1da-9822-4a6b-913c-c1af0ca5b29d).html

Richard Unsworth, Swansea University
[Email Address Removed]
www.swansea.ac.uk/staff/science/biosciences/r.k.f.unsworth/

Richard Lilley, Project Seagrass
[Email Address Removed]
www.projectseagrass.org/richard-lilley